Noise baffling method and apparatus for a washing appliance

ABSTRACT

For a washing machine such as a dishwasher or the like having a substantially large volume drainage conduit means extending from the machine&#39;&#39;s washing chamber to a receiving pump situated downstream from the washing chamber, a method is provided for baffling pump noise normally emitted from the drainage conduit when drainage flow begins to ebb at the end of a chamber drainage operation. Apparatus is provided for implementing the method described, including valve means adapted to substantially close off the cross-sectional area of the drainage conduit when drainage flow diminishes.

United States Patent [72] Inventor Lauren W. Guth 1,955,479 4/1934 Weinberger 18l/36UX Louisville, Ky. 2,878,826 3/1959 Dolenga 137/216 [21] Appl. No. 831.3916196 3,244,105 4/1966 Laflame 415/143 1 Fi ed 9 FOREIGN P TENT [45] Patented Mar. 9, 1971 656 983 1/1929 F A S [73] Assignee General Electric Company rance 181 /64( .2)

Primary Examiner-Robert S. Ward, Jr. Attorneys-James E. Espe, Harry F. Manbeck, Jr., Joseph B. 1 NOISE BAFFUNG METHOD AND APPARATUS Forman, Oscar B. Waddell and Frank L. Neuhauser FOR A WASHING APPLIANCE 1 Y 11 Claims, 5 Drawing Figs. p [52] US. Cl 181/36, ABSTRACT; For a washing machine sugh as a dishwasher 01:

181/37, 181/65 the like having a substantially large volume drainage conduit [5l] lllLCl Foln 1/16, means xt ndi g from the machines washing chamber to a F0111 receiving pump situated downstream from the washing chamber a method is provided for pump noise nor. 37 mally emitted from the drainage conduit when drainage flow begins to ebb at the end of a chamber drainage operation. Ap- [56] Rat-mum Cited paratus is provided for implementing the method described, UNITED STATES PATENTS including valve means adapted to substantially cI'ose off the 947,431 1/1910 DeGrandsagne 181/36 cross-sectional area of the drainage conduit when drainage 1 5 9 ,924 g/1925wan a. 181 /64(.2) flow diminishes.

INVENTOR. LAUREN W. GUTH BY 34 TWJQK ms ATTORNEY NOISE BAFFLING METHOD AND APPARATUS FOR A WASHING APPLIANCE BACKGROUND OF THE INVENTION This invention relates generally toa washing machine such as a dishwasher or the like having a recirculation and drainage pump connected by drainage conduit means to its washing chamber. The invention particularly pertains to both a method and means for baffling or reducing the level of audible emissions from a recirculation or drainage pump at the completion of a chamber drainage operation.

An automatic dishwasher conventionally has a complete cycle of operation which includes several admissions of water, each of which is followed by a wash or rinse operation wherein the water, or water having detergents or other additives mixed therewith, is recirculated through a washing chamber. After a suitable length of time, the recirculation is terminated and the washing liquid is discharged from the dishwasher into the household sewer system. Both the recirculation and the discharge of the washing liquid requires the use of a pump. It is conventional in many types of dishwashers. to provide, for draining to the pump, a substantially large sump disposed below the lowest point in the floor portion or bottom wall of the washing chamber.. The sump receives the accumulated washing liquid and conducts it downwardly through an opening therefrom to the pump. The pump operates to either discharge the washingaliquid from the dishwasher or to recirculate the washing liquid to and from the washing chamber. The sump and its associated drainage conduit generally have a substantially large cross sectional drainage area to facilitate an unimpeded rapid recirculation or drainage to the pump located below the washing chamber bottom wall. I

A problem associated with the types of dishwasher heretofore generally described is that the pump tendsto produce a loud pulsating noise during pump-out. This noise occurs mainly during the final period of pump-out when the-machine has little or no water in it. This noise, which is generated by the rotating impeller of the pump sucking air along with the residual water being pumped therethrough, tends to reverberate upwardly through the drain connector or conduit to the sump and into the dishwasher tub or washing chamber.'From there the noise is transferred to the cabinet structure and emittedoutwardly through the wash chamber vents into the kitchen area.

Several ways have been attempted in the past to eliminate or reduce the aforementioned noise. One way has been the adaption of the dishwasher timer controlwhereby the motor that energizes the pump is not operated during fill periods in the washing cycle so that at least the harsh noise generated by the pump running with less than a full charge of water is eliminated during such periods. This method does not solve 'the problem of pump noise at the end of a pump-out operation. Another arrangement for reducing the audible reverberation from the pump has involved raising the sump'to create a dam around the center drain opening of the sump. This creates an annular cavity around the center drain opening in the sump, and with the provision therewith of a domeshaped sump cover positioned so that its outer edge extends into the annular cavity to form a circular trap," much of the harsh sound generated by the pump is baffled and absorbed before it reaches the washing chamber.

Several problems are associated .with the latter arrangement. One problem is that the sump itself must be substantially large in order to incorporate the annular cavity and its associated sump cover therewith. Also, the annular cavity tends to accumulate a carry over of comparatively dirty washing liquid and food soil that mixes with the clean water entering the machine in the next wash or rinse step.

Therefore, it is an objective of the present invention to provide an improved and simplified method and means of reducing and baffling the noise that is generated by the pump means of an automatic washing machine, particularly a dishwasher, at the end of a drainage operation in its washing cycle.

It is a further objective of the present-invention to accom plish the foregoing primary objective in a manner which will eliminate the need for the use of an annular trap and associated sump cover and thereby simplify the sump construction and attain a reduction in size and cost of drainage components. I

SUMMARY OF THE INVENTION In accordance with the foregoing objectives, the present invention provides a method and apparatus for baffling noise normally associated with the pump means of an automatic ar-' ticle washing machine such as a dishwasher. The method and apparatus are particularly applicable to the type of article washing machine having a drain opening in its bottomwall for collecting accumulated washing liquid and conducting it from the washing chamber to a pump means capable of either recirculating the washing liquid through the washing chamber or discharging it from the machine to the household sewage system. The method broadly includes a first step of choking off the drainage means of the machine to substantially reduce its total cross-sectional drainage area, substantially at the time the drainage diminishes to a comparatively lesser flow occupying substantially less than the available cross-sectional area of the drainage means. A second step may be a provision means for bypassing the point of occurrence of the choking operation so that residual washing fluid in the washing chamber can continue to flow to the pump means though the major drainage channel has been substantially blocked to baffle pump noise normally emitted through the drainage means at the end of the machine s discharge operation.

The apparatus for effecting this method includes valve means for substantially closing or restricting the drainage conduit at the proper time. Two preferred constructions for such valve means, described in detail hereinafter, are (1.) a liquid level responsive valve assembly, and (2) a liquid pressure" responsive valve assembly.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 is an elevational view, partially cutaway to show the details, of an automatic dishwashing 'machine in which the present invention may be utilized; I

FIG. 2 is an elevational view, shown partially in cross section, of one construction, first shown in FIG. 1, of apparatus for effecting the method of the present invention;

FIG. 3 is an elevational view in vertical cross section show ing an alternative arrangement of the construction shown in FIG. 2;

FIG. 4 is an elevational view in vertical cross section ofa second construction of apparatus for performing the method of the present invention;

FIG. 5 is a view in horizontal cross section of the construction shown in FIG. 4 as it would be seen if viewed downwardly substantially along line 5-5, of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawing, and particularly to FIG. 1 thereof, there is illustrated an automatic dishwashing machine having an outer cabinet 10 constructed of opposed sidewalls 11 and 12, an upper or top wall 13, and a backwall 14. The front side of the dishwasher is made up of a substantially large hinged cover or door 15 and a lower front panel 16. Disposed behind the door 15 is a substantially large washing chamber 17, the lower extremity of which is defined by a bottom wall or floor portion 18. The door 15 is pivotal about a hinge means located atthe lower edge thereof so that when the door 15 is pivoted downwardly to provide access to the washing chamber 17, slidably mounted dish supporting racks l9 and 20 can be at least partially withdrawn from the washing chamber 17 to facilitate loading and unloading of the racks with dishes and tableware.

Located below the wash chambers bottom wall 18 is a motor-pump compartment 21 wherein a motor-pump assembly 25 is housed. The motor-pump assembly 25 includes a pump 26 capable of recirculating washing liquid to and, from the washing chamber 17, an electric motor 27 for driving the pump 26, and an electrically actuated switch 29 for operating a valve (not shown) to selectively divert the outlet of the pump 26 between a substantially large recirculation conduit 29 and a smaller discharge conduit 33.

M It will be noted that the bottom wall 18 is provided with a central upwardly protruding portion or hump 30 through which the conduit 29 extends. The conduit 29 acts also as a pedestal on which a rotatable spray arm 31 is mounted. During the recirculation operation of the motor-pump assembly 25, washingliquid is pumped upwardly from the pump 26 through the conduit 29 and into the hollow spray arm 31. The sprayarrn 31 is provided with a plurality of spacedapart orifices 32 along the top surface thereoffor distributing a spray jlpattern of washing liquid upwardly upon the dishes supported in the racks l9 and in the-washing chamber 17. Conventionally, at least one of the orifices 32 provided on the spray arm 31 is oriented to provide a reactive jet spray to thereby rotate the spray arm 31 on the upper end of the conduit 29.

A relatively large circular opening 35 is provided in the bottom wall 18 in a position laterally adjacent the hump 30, and a large sump or funnellike well 36 is connected to form, in combination with a drainage conduit 39, a drainage means for the washing chamber 17. The sump 36 extends downwardly into the motor-pump compartment 21 and has a lower open end connected in fluid flow communication with the discharge conduit 39 that leads to the inlet side of the pump 26. Clamps 40 are provided for joining the ends of the discharge conduit 39 in fluid flow relation to the lower end of the sump 36 and the input side of the pump 26, respectively.

The sump 36 is typical of the construction of the type of sump used in combination with the sump cover (not shown) heretofore described. As shown, the upper end of the sump 36 is constructed with an annular downwardly depressed cavity 41 to create a circumjacent annular upwardly projecting ridge or dam 42. A sump cover could be horizontally disposed in the upper end of the sump structure 'so that its downwardly curved outer peripheral edge would extend into the cavity 41 and thus create a circular trap through which all washing liquid drained from the washing chamber 17 must pass on its way downwardly through the sump 36 to the conduit 39.

One embodiment or construction of the apparatus for performing the method of the present invention may be employed in combination with the aforementioned typical sump construction, obviating the need for a sump cover. As shown in FIGS. 1 and 2, a liquid displacing member or float 44 is provided as a means of obstructing the washing chamber drainage opening to thereby absorb and deflect and effectively baffle sound through the conduit 39 from the machines pump 26. The float 44 may be constructed to have an upper disclike body portion 45 and a lower radially inwardly sloped portion 46. An open frame work cage 50 may be positioned over the sump 36 and be fastened in position by means of fasteners 51 so that the float 44 will be retained in vertical alignment above the wash chambers drain opening.

The float 44 is adapted to be displaced by the water during the fill operation of the machine. Then, as the water level in the washing chamber 17 recedes to a point where liquid flowing into the sump 39 in the washing chambers bottom wall no longer is enough to fill the cross-sectional area of the opening 37 in the sumps lower end, the float 44 drops into and substantially occupies the opening 37 to absorb and deflect sound emitted from the pump 26. In the utilization of this apparatus, the means for bypassing the float member 44 that occupies the opening 37 may be a plurality of substantially narrow grooves disposed in a spaced-apart relation around the outer periphery of the float 44.

As previously stated, the use of the described float valve apparatus enables the method of the present invention to be practiced in combination with a conventional sump structure (as shown in FIG. 1) simply by discarding the sump cover (not shown) and installing the assembly, including the float 44 and the cage 50, in the sump 36. This has the advantage of permitting this construction to be incorporated in existing machines without the immediate need for retooling to produce a modified washing chamber bottom wall and a modified sump. However, since this construction of the apparatus obviates the need for the dam 42 and the annular cavity 41, a'modified form for a sump, such as sump 37 in FIG. 3, may also be provided for use with the float 44. As shown in FIG. 3, the sump 37 is about the size of the intermediate or throat portion 36a of the sump 36 shown in FIG. 1, and the dam. 42 and annular cavity 41 have been completely eliminated.

In FIGS. 4 and 5 another form of apparatus for the-present invention is illustrated. A flapper type hinged planar valve member 54 is disposed within a drain sleeve 53, and is pivotally connected to the straight inner edge of a semicircular ledge or fixed shelf 56 by means of a horizontally disposed hinge arrangement or pivot pin 55. A biasing means in the form of a bent wire spring 57 is provided for urging the flapper valve 54 toward its normally closed position (FIG. 4), and an integral fingerlike portion 58 of the flapper valve member 54 extends outwardly intermediate the straight edge portion thereof to act as a stop means for preventing the member 54 from being urged upwardly by the spring 57 past the closed position.

The sleeve 53 illustrated in FIG. 4 can be utilized in place of the sump 36 (FIG. 1) in connection with a drain opening provided in the washing chambers bottom wall 18. The lower end of the sleeve 53 may be extended to attain proper fluid flow connection with the conduit 39 or the conduit 39 itself may be modified to connect to the sleeveconstruction shown in FIG.

In the operation of a washing machine utilizing the embodiment illustrated in FIGS. 4 and 5, the valve member 54 would tend to respond to the force of washing liquid being drained from the machines washing chamber and downward through the sleeve 53 and would be forced to and held in the open position (FIG. 4) so long as a substantial flow of washing liquid was draining or recirculating therethrough. Near the end of the particular drainage operation, as the water level in the washing chamber receded and the drainage flow through the sleeve 53 diminished to the point where the force of the drainage flow would be less than the counteracting force of the spring 57 the valve member 54 would be urgedby the spring 57 to its closed position (FIG. 5) to substantially choke off the passage and thereby baffle the sucking sound characteristically emitted from the pump housing when the pump is no longer receiving a full flow of the drainage liquid.

With the apparatus shown in FIGS. 4 and 5, the means of allowing for residual drainage after the valve member 54 has substantially closed off the passage through the sleeve 53 can be accomplished by constructing the valve member 54 with a slightly smaller diameter than the inside diameter of the sleeve 53 so that the final accumulation of washing liquid moving downward through the sleeve 53 can pass between the peripheral edge of the valve member 54 and the inside surface of the sleeve 53.

The described alternative constructions for accomplishing the method of the present invention do not rule out the possibility of practicing the method by other structural means. The described embodiments, however, are presently preferred because they have been satisfactorily tested and have proven to be inexpensive to produce and reliable for their intended purpose. During laboratory tests of a valve means of the type shown in FIG. 2, it was ascertained that the method of the present invention could also be accomplished by constructing a float or liquid displacing member 44 without the grooves 47, so long as the member 44 was a misfit in the throat of the sump 36 'such that residual liquid could still pass around the outer circumferential edge of the member 44 and thence into the drainage conduit 39 therebelow. It was also determined, in reference to the embodiment shown in FIG. 4, that the valve member 54 may be constructed to substantially seal against the inner wall of the sleeve 53 when the valve member 54 is in its closed position, and that the means for completing residual drainage can be a small hole provided through the valve member 54. For example, it was determined that a ririnch hole through the valve member 54 is sufficient for final drainage and does not interfere with the attainment of the noise baffling effect of the apparatus.

Iclaim:

1. A method of baffling noise in an article washing machine having a washing chamber with drainage means including a sump for conducting washing liquid from the washing chamber to thepump, comprising the steps of:

a. choking off the drainage means to substantially reduce its total cross-sectional area approximately at the time the drainage therethrough diminishes to a flow occupying substantially less than the available cross-sectional area of the drainage means, and

b. providing bypass means of relatively small cross-sectional area leading from the washing chamber and past the point of occurrence of said choking operation whereby remaining washing liquid in the washing chamber may flow to the pump so as to substantially evacuate all the washing fluid from the washing chamber.

2. The method of claim 1 further including,

c. splitting the bypass means into a plurality of substantially smaller spaced apart openings each bypassing the point of occurrence of said choking operation. 7

3. A method of battling noise in an article washing machine having a washing chamber with drainage means including a' sump for conducting drainage liquid from the washing chamber to the pump, I

a. first, causing a major portion of the liquid to be drained to pass through said drainage means;

b. then, substantially reducing the cross-sectional area of the drainage means to baffle the pump-emitted noise, and;

c. completing residual drainage of the liquid to be drained through the'remaining nonrestricted drainage area.

4. In an article washing machine such as a dishwasher or the like having a substantially high volume drainage means disposed to receive washing liquid from a washing chamber and conduct it to a downstream pump means, means for baffling noise that may tend to reverberate from the pump means, through the drainage means and into the washing chamber when the high volume drainage flow of washing liquid through said conduit begins to diminish at the end of a drainage cycle, said battling-means including, valve means operable to substantially restrict the cross-sectional area of said drainage means substantially at the time that drainage flow therethrough begins to diminish to the point where reverberation noise from said pump means would be audible.

5. The invention of claim 4 wherein said valve means is adapted to be responsive to diminishing drainage pressure whereby it acts to substantially choke off the cross-sectional drainage area and thereby baffle pump-emitted noise at about the end of a drainage cycle. g

6. The invention of claim 4 wherein said'valve means is a liquid level responsive valve assembly disposed to respond to the level of liquid in the machines washing chamber.

7. The invention of claim 4 wherein said valve means is positioned in the drainage means at a point immediately adjacent the drain opening in the floor portion of the machines washing chamber.

8. The invention of claim 4 wherein said valve means is disposed in said drainage means, and a bypass means is provided to permit low level drainage past the area of said valve when said valve is in its closed position.

9. The invention of claim 4- wherein said valve means further comprises a liquid displacing member adapted to operate in conjunction with the drain opening in the floor portion of the machlnes washing chamber in res nctmg the crosssectional area of the drainage means as the drainage flow therethrough begins to diminish at the end of a drainage operation in the washing cycle of the machine.

10. The invention set forth in claim 9 wherein a bypass for conducting residual drainage flow past said liquid displacing member is provided, and said by pass means has a substantially small cross-sectional drainage area such that residual drainage at the end of a drainage operation may be completed while the major cross-sectional area of said drainage means is restricted by said liquid displacing member.

11. The invention set forth in claim 4 wherein said valve means further comprises a hinged valve member adapted to pivot and assume a closed position to act as a barrier extending transversely to the path of drainage flow through said drainage means. 

1. A method of baffling noise in an article washing machine having a washing chamber with drainage means including a sump for conducting washing liquid from the washing chamber to the pump, comprising the steps of: a. choking off the drainage means to substantially reduce its total cross-sectional area approximately at the time the drainage therethrough diminishes to a flow occupying substantially less than the available cross-sectional area of the drainage means, and b. providing bypass means of relatively small cross-sectional area leading from the washing chamber and past the point of occurrence of said choking operation whereby remaining washing liquid in the washing chamber may flow to the pump so as to substantially evacuate all the washing fluid from the washing chamber.
 2. The method of claim 1 further including, c. splitting the bypass means into a plurality of substantially smaller spaced apart openings each bypassing the point of occurrence of said choking operation.
 3. A method of baffling noise in an article washing machine having a washing chamber with drainage means including a sump for conducting drainage liquid from the washing chamber to the pump, a. first, causing a major portion of the liquid to be drained to pass through said drainage means; b. then, substantially reducing the cross-sectional area of the drainage means to baffle the pump-emitted noise, and; c. completing residual drainage of the liquid to be drained through the remaining nonrestricted drainage area.
 4. In an article washing machine such as a dishwasher or the like having a substantially high volume drainage means disposed to receive washing liquid from a washing chamber and conduct it to a downstreaM pump means, means for baffling noise that may tend to reverberate from the pump means, through the drainage means and into the washing chamber when the high volume drainage flow of washing liquid through said conduit begins to diminish at the end of a drainage cycle, said baffling means including, valve means operable to substantially restrict the cross-sectional area of said drainage means substantially at the time that drainage flow therethrough begins to diminish to the point where reverberation noise from said pump means would be audible.
 5. The invention of claim 4 wherein said valve means is adapted to be responsive to diminishing drainage pressure whereby it acts to substantially choke off the cross-sectional drainage area and thereby baffle pump-emitted noise at about the end of a drainage cycle.
 6. The invention of claim 4 wherein said valve means is a liquid level responsive valve assembly disposed to respond to the level of liquid in the machine''s washing chamber.
 7. The invention of claim 4 wherein said valve means is positioned in the drainage means at a point immediately adjacent the drain opening in the floor portion of the machine''s washing chamber.
 8. The invention of claim 4 wherein said valve means is disposed in said drainage means, and a bypass means is provided to permit low level drainage past the area of said valve when said valve is in its closed position.
 9. The invention of claim 4 wherein said valve means further comprises a liquid displacing member adapted to operate in conjunction with the drain opening in the floor portion of the machine''s washing chamber in restricting the cross-sectional area of the drainage means as the drainage flow therethrough begins to diminish at the end of a drainage operation in the washing cycle of the machine.
 10. The invention set forth in claim 9 wherein a bypass for conducting residual drainage flow past said liquid displacing member is provided, and said by pass means has a substantially small cross-sectional drainage area such that residual drainage at the end of a drainage operation may be completed while the major cross-sectional area of said drainage means is restricted by said liquid displacing member.
 11. The invention set forth in claim 4 wherein said valve means further comprises a hinged valve member adapted to pivot and assume a closed position to act as a barrier extending transversely to the path of drainage flow through said drainage means. 